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authorBjörn Gustavsson <[email protected]>2018-09-28 05:57:47 +0200
committerBjörn Gustavsson <[email protected]>2018-09-28 10:47:56 +0200
commit0bb261b730eff06cca524ea9999ff035585ef5b4 (patch)
treee057e70bc7fe53a7ec74577dfdb836707e7ae60b /lib/compiler/test
parent377f19f25aeec6939a6728bd0c4910086c22ccdc (diff)
downloadotp-0bb261b730eff06cca524ea9999ff035585ef5b4.tar.gz
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Fix rare bug in binary matching (again)
2e40d8d1c51a attempted fix a bug in binary matching, but it only fixed the bug for the minimized test case. This commit removes the previous fix and fixes the bug in a more effective way. See the comments in the new code in `sys_core_bsm` for an explanation. This commit restores the optimizations in string.erl and dets_v9.erl that the previous fix disabled. I have not found any code where this commit will disable optimizations when they are actually safe. There are some changes to the code in ssl_cipher.erl in that some bs_start_match2 instruction did not reuse the binary register for the match context, but the delayed sub binary optimizations was never applied to the code in the first place. https://bugs.erlang.org/browse/ERL-689
Diffstat (limited to 'lib/compiler/test')
-rw-r--r--lib/compiler/test/bs_match_SUITE.erl38
1 files changed, 35 insertions, 3 deletions
diff --git a/lib/compiler/test/bs_match_SUITE.erl b/lib/compiler/test/bs_match_SUITE.erl
index 7814738449..e97dbac8a6 100644
--- a/lib/compiler/test/bs_match_SUITE.erl
+++ b/lib/compiler/test/bs_match_SUITE.erl
@@ -1690,30 +1690,62 @@ non_opt_eq([], <<>>) ->
%% ERL-689
-erl_689(Config) ->
+erl_689(_Config) ->
{{0, 0, 0}, <<>>} = do_erl_689_1(<<0>>, ?MODULE),
{{2018, 8, 7}, <<>>} = do_erl_689_1(<<4,2018:16/little,8,7>>, ?MODULE),
{{0, 0, 0}, <<>>} = do_erl_689_2(?MODULE, <<0>>),
{{2018, 8, 7}, <<>>} = do_erl_689_2(?MODULE, <<4,2018:16/little,8,7>>),
ok.
-do_erl_689_1(<<Length, Data/binary>>, _) ->
+do_erl_689_1(Arg1, Arg2) ->
+ Res = do_erl_689_1a(Arg1, Arg2),
+ Res = do_erl_689_1b(Arg1, Arg2).
+
+do_erl_689_2(Arg1, Arg2) ->
+ Res = do_erl_689_2a(Arg1, Arg2),
+ Res = do_erl_689_2b(Arg1, Arg2).
+
+do_erl_689_1a(<<Length, Data/binary>>, _) ->
+ case {Data, Length} of
+ {_, 0} ->
+ %% bs_context_to_binary would incorrectly set Data to the original
+ %% binary (before matching in the function head).
+ {{0, 0, 0}, Data};
+ {<<Y:16/little, M, D, Rest/binary>>, 4} ->
+ {{Y, M, D}, Rest}
+ end.
+
+do_erl_689_1b(<<Length, Data/binary>>, _) ->
case {Data, Length} of
{_, 0} ->
%% bs_context_to_binary would incorrectly set Data to the original
%% binary (before matching in the function head).
+ id(0),
{{0, 0, 0}, Data};
{<<Y:16/little, M, D, Rest/binary>>, 4} ->
+ id(1),
+ {{Y, M, D}, Rest}
+ end.
+
+do_erl_689_2a(_, <<Length, Data/binary>>) ->
+ case {Length, Data} of
+ {0, _} ->
+ %% bs_context_to_binary would incorrectly set Data to the original
+ %% binary (before matching in the function head).
+ {{0, 0, 0}, Data};
+ {4, <<Y:16/little, M, D, Rest/binary>>} ->
{{Y, M, D}, Rest}
end.
-do_erl_689_2(_, <<Length, Data/binary>>) ->
+do_erl_689_2b(_, <<Length, Data/binary>>) ->
case {Length, Data} of
{0, _} ->
%% bs_context_to_binary would incorrectly set Data to the original
%% binary (before matching in the function head).
+ id(0),
{{0, 0, 0}, Data};
{4, <<Y:16/little, M, D, Rest/binary>>} ->
+ id(1),
{{Y, M, D}, Rest}
end.